Diaphragm-horn.



M. R. HUTGHISON.

DIAPHRAGM HORN.

APPLIGATION FILED AUG. 26, 1014.

Patented Dec. 8, 1914.

purpose.

' E STES PATENT FIQE.

MILLER REESE HU'ICHISON, OF WEST ORANGE, NEW JERSEY, ASSIGNOR T0 LOVELL-MOCONNELL MANUFACTURING COMPANY, A CORPORATION OF DELAWARE.

DIAPHRAGM-HORN.

Specification of Letters Patent.

Patented Dec. 8, 1914.

Original application filed October 26, 1909, Serial No. 524,762. Dividedand this application filed August 26, 1914. Serial No. 858,676.

T 0 all whom it may concern:

Be it known that I, MILLER Rnnsn Huron- ISON, a citizen of the UnitedStates, and a resident of West Orange, in the county of Essex and Stateof New Jersey, have invented certain new and useful Improvements inDiaphragm-Horns, of which the following is a specification.

My present invention relates to horns or signaling devices wherein adiaphragm is vibrated by a rotary cam mounted on a suit able shaft suchfor instance as the armature shaft of an electric motor. In my priorPatent 923,122, I have disclosed one form of motor, motor support andcam to operate the diaphragm, and in my co-pending application, Ser. No.524,762, filed October 26th, 1909, of which the present application is adivision, I have shown other forms in which I employ such an arrangementof parts that the vibrator} motion of the diaphragm may be derived fromthe armature shaft of an electric motor, with such shaft arranged at anangle to the plane of the dia phragm instead of parallel therewith. Thisis particularly desirable, since it permits a compact arrangement of theelectric motor within a case which need not extend peripherally outsideof the circumference required for inclosing the diaphragm. In theparticular form hereinafter described, the mo tor is arranged with itsarmature at an acute angle to the diaphragm, and the axis of the shaftis out of alinement with the center of the diaphragm. By means of thisarrangement, the center of mass or volume of the motor may be broughtclose to a perpendicular from the center of the diaphragm, and at thesame time the cam surfaces adjacent to the periphery of a rotor mayoperate at the center of the diaphragm.

My invention involves other features of importance which will be pointedout in connection with the description of one prac tical embodimentthereof shown in the accompanying drawing in which the figure is avertical section longitudinally of the drive shaft, the motor beingshown in elevation.

In the drawing the horn or resonator 1, front case 2, peripheral flange3, diaphragm 4, clamps 5, 6, and cork-like gaskets 7 8, are of any knownconstruction suitable for the The wear piece 72, secured to thecenter-of the diaphragm, may be of any known or approved construction,but is preferably formed for straight line contact with the rotarydisplacing member. The drive shaft 10 carries a rotary member 70provided with teeth or projections 76, the latter being projections on abevel face, preferably cut in accordance with the well known principlessimilar to those established for teeth of bevel or crown gears, so thattheir sliding engagement with the diaphragm projection 72 will not varymuch with its axial projections intersecting at a point eccentric to thediaphragm by an amount approximately equal to the radius of the facecam. Obviously, the eccentricity of the axial projection of the motorshaft may be decreased by decreasing the diameter of the face cam or bytilting the motor to a greater extent, but preferably the center of massor volume of the motor, lies practically in a line perpendicular to theaxis of the diaphragm. The size of the rotary member 70, the angle ofinclination of the axis and the eccentricity of the point ofintersection of axial projection of shaft and diaphragm are preferablyinterdependent in order to keep the mass of the motor close to a lineperpendicular to the diaphragm passing through the center thereof. Bythis arrangement the motor may he brought well within the periphery ofthe diaphragm clamps 5, 6 and aseparate case 73 for the motor may beemployed which is also of less diameter than said clamps and issymmetrical with respect to the axis of the horn 1. The teeth orprojections 76 on the rotor and the wear piece on the diaphragm areformed so that the elements thereof produce true contact and aresubstantially parallel with the diaphragm. Thus the angle of the axisand the angle or bevel of the teeth are interdependent. The rear clamp 6of the diaphragm involves an important feature of my invention. Itcarries preferably integral therewith, an arm 74 having an inclinedupper surface to which the motor is detachably connected by a bolt 7 5passing through a slot 7 6 shown in dotted lines. This support andconnection for the motor should be formed so that adjustment of therotary member 70 to and from the wear piece ?2 on the diaphragm may beeffected. In form shown such adjustment is permitted by the slot in thearm and is along a line parallel to the axis of the motor.

. By reason of the angular mounting of the motor shaft, a given axialadjustment produces a lesser movement of the rotor diprovided with anordinary thrust bearing for the armature shaft within the boss 78. Withthis construction the parts may all be assembled and tested without therear case, the latter being applied over the flange 79 and securedthereto as by screws 80. The inclined arrangement of the drive shaft hasthe further advantage that the device may be secured in position so thatgravity keeps the shaft normally in contact with the rear thrustbearing, thereby insuring uniform extent of overlap of camand wear pieceregardlessof any endwise play of the shaft such as is usually providedfor to insure free running in small electric motors of the type herecontemplated. This tends to make starting easier and more certain as thecam is always at its maximum distance from the diaphragm. It alsoeliminates the possibility of slight endwise chattering of the shaftsuch as is likely to occur under certain conditions, particularly atstarting and stopping when the cam contacts are least har monious withthe natural bodily swing of the diaphragm.

While I have herein fully shown and described, and have pointed out in.the appended claims certain novel features of construction, arrangement,and operation which characterize my invention, it will be understood bythose skilled in the art that various omissions, substitutions, andchanges in the forms, proportions, sizes, and details of the device andof its operation, may be made without departing from my invention.

Having thus described my invention, what I claim as 'new and desire tosecure by Letters Patent, is

1-. In an alarm or signaling device, a diaphragm, and mechanical meansincluding a drive shaft disposed at an acute angle to said diaphragm forvibratipg the latter in combination with means for supporting said partswith the center of volume of the driv ing mechanism close to a line"passing through the axis of the horn and the center of the diaphragm.

2. In an alarm or signaling device, a diaphragm, and mechanical meansincluding an electric motor for vibrating said diaphragm in combinationwith means for supporting said parts with the motor shaft at an acuteangle to the plane of the diaphragm, and with the center of mass of themotor substantially in a line noymal to the diaphragm at the center ofthe latter. M

3. In an alarm or signaling device, adiaphragm and mechanical meansincluding an electric motor for vibrating said diaphragm in combinationwith means for supporting said parts with the motor shaft at an acuteangle to.the plane of the diaphragm, the

motor and diaphragm being proportioned and arranged so that themechanical driving means does not project peripherally beyond thecircumference of the diaphragm supporting means, together with a caseconforming to and including all said parts.

4. In an alarm or signaling device. a diaphragm normally disposed in asubstantially vertical plane and having a wearpiece, an electric motorhaving the axis of its shaft disposed at an acute angle to the plane ofthe diaphragm and inclined downwardly and rearwardly from a point abovesaid Wearpiece and the center of mass of the motor being substantiallyin a\line normal to the diaphragm and passing through said wearpiece,and a rotor on the shaft of said motor and having its center above saidwearpiece and presentin beveled projections adjacent its periphery forengagement with the latter.

5. In an alarm or signaling device, a diaphragm having a Wearpiece, abeveled face cam for vibrating said diaphragm and a shaft carrying saidrotor and disposed at an acute angle to the plane of said diaphragm,'

the inclination of said shaft and the angle of bevel of said face cambeing proportioned to produce line contact between cam and Wearpiece.

6. In an alarm or signaling device, a diaphragm having a wearpiece, arotor presenting cam projections for engagement with said wearpiece tovibrate said diaphragm, a shaft supporting said rotor and disposed at anacute angle to the plane of said diaphragm, a motor for rotating saidshaft the center of mass of said motor being sub stantially in a linenormal to said diaphragm and passing through said Wearpiece and theinclination of said shaft and the size of said rotor beinginterdependent.

s. In an alarm or signaling device, a diaagainst which said shaft isretained by gravity.

8. In an alarm or si aling device, a diaphragm, a drive shatt presentedendwise to said diaphragm and adjustable in a direc tion at an acuteangle to said diaphragm, and a rotor carried by said shaft for vibratingsaid diaphragm.

9. In a horn or signaling device, a diaphragm, a diaphragm clamp havinga slotte'd bracket integral therewith and present ing the downwardly andrearwardly inclined upper face, and an electric motor mounted on saidbracket and adjustable along said inclined face.

10. In an alarm or signaling device, a diaphragm normally disposedsubstantially in a vertical plane, a diaphragm clamped for engagementwith the peripheral portion of said diaphragm and having an armextending rearwardly therefrom and presenting a downwardly andrearwardly inclined upper face, an electric motor mounted on theinclined upper face of said arm and having its center of masssubstantially in a line at ri ht angles to the diaphragm at the centeroi? the latter, means for adjusting said motor bodily toward and. fromsaid diaphragm and a rotor carried by the armature shaft of said motorand disposed above the center of said diaphragm and presenting beveledcam projections for engagement with the diaphragm substantially at thecenter of the latter.

11. In an alarm or signaling device, a diaphragm, a diaphragm clampingmember having a r earwardly projecting annular flange and an arm integalwith said flange and within the periphery of the latter and projectingrearwardly therefrom, and having a slot extending lengthwise thereof, ahigh speed, rotary, electric motor, means extending through said slotfor detachably and adjustably securing said motor to said arm, and athin sheet metal case inclosing said motor and said arm and telescopingwith and detachably secured to said flange.

12. In an alarm or signaling device, a diaphragm, a diaphragm clampingmember having an arm integral therewith and projecting rearwardlytherefrom, adjacent one edge only of the diaphragm and having a slotextending lengthwise thereof, a high speed, rotary, electric motorhaving its shaft presented endwiseto said diaphragm, means .earried bysaid motor for vibrating said diaphragm, means extending through saidslot for detachably and adjust-ably securing said motor to said arm, anda thin sheet metal case inclosing said motor and arm and detachablysecured to said clamping member.

Signed at \V est Orange in the county of Essex and State of New Jerseythis 24th day of August, 1914.

MILLER REESE HUTCHISON.

Witnesses FREDERICK BAOHMANN, A. B. M. EsnoL1n.

